//===--- TargetInfo.h - Expose information about the target -----*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
//  This file defines the TargetInfo interface.
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_CLANG_BASIC_TARGETINFO_H
#define LLVM_CLANG_BASIC_TARGETINFO_H

// FIXME: Daniel isn't smart enough to use a prototype for this.
#include "llvm/ADT/StringMap.h"
#include "llvm/Support/DataTypes.h"
#include <cassert>
#include <vector>
#include <string>

namespace llvm {
struct fltSemantics;
class StringRef;
}

namespace clang {

class Diagnostic;
class SourceLocation;
class SourceManager;
class LangOptions;
namespace Builtin { struct Info; }
  
/// TargetInfo - This class exposes information about the current target.
///
class TargetInfo {
  std::string Triple;
protected:
  // Target values set by the ctor of the actual target implementation.  Default
  // values are specified by the TargetInfo constructor.
  bool TLSSupported;
  unsigned char PointerWidth, PointerAlign;
  unsigned char WCharWidth, WCharAlign;
  unsigned char Char16Width, Char16Align;
  unsigned char Char32Width, Char32Align;
  unsigned char IntWidth, IntAlign;
  unsigned char FloatWidth, FloatAlign;
  unsigned char DoubleWidth, DoubleAlign;
  unsigned char LongDoubleWidth, LongDoubleAlign;
  unsigned char LongWidth, LongAlign;
  unsigned char LongLongWidth, LongLongAlign;
  unsigned char IntMaxTWidth;
  const char *DescriptionString;
  const char *UserLabelPrefix;
  const llvm::fltSemantics *FloatFormat, *DoubleFormat, *LongDoubleFormat;
  unsigned char RegParmMax, SSERegParmMax;

  // TargetInfo Constructor.  Default initializes all fields.
  TargetInfo(const std::string &T);
  
public:  
  /// CreateTargetInfo - Return the target info object for the specified target
  /// triple.
  static TargetInfo* CreateTargetInfo(const std::string &Triple);

  virtual ~TargetInfo();

  ///===---- Target Data Type Query Methods -------------------------------===//
  enum IntType {
    NoInt = 0,
    SignedShort,
    UnsignedShort,
    SignedInt,
    UnsignedInt,
    SignedLong,
    UnsignedLong,
    SignedLongLong,
    UnsignedLongLong
  };
protected:
  IntType SizeType, IntMaxType, UIntMaxType, PtrDiffType, IntPtrType, WCharType,
          Char16Type, Char32Type, Int64Type;
public:
  IntType getSizeType() const { return SizeType; }
  IntType getIntMaxType() const { return IntMaxType; }
  IntType getUIntMaxType() const { return UIntMaxType; }
  IntType getPtrDiffType(unsigned AddrSpace) const {
    return AddrSpace == 0 ? PtrDiffType : getPtrDiffTypeV(AddrSpace);
  }
  IntType getIntPtrType() const { return IntPtrType; }
  IntType getWCharType() const { return WCharType; }
  IntType getChar16Type() const { return Char16Type; }
  IntType getChar32Type() const { return Char32Type; }
  IntType getInt64Type() const { return Int64Type; }

  /// getPointerWidth - Return the width of pointers on this target, for the
  /// specified address space.
  uint64_t getPointerWidth(unsigned AddrSpace) const {
    return AddrSpace == 0 ? PointerWidth : getPointerWidthV(AddrSpace);
  }
  uint64_t getPointerAlign(unsigned AddrSpace) const {
    return AddrSpace == 0 ? PointerAlign : getPointerAlignV(AddrSpace);
  }
  
  /// getBoolWidth/Align - Return the size of '_Bool' and C++ 'bool' for this
  /// target, in bits.
  unsigned getBoolWidth(bool isWide = false) const { return 8; }  // FIXME
  unsigned getBoolAlign(bool isWide = false) const { return 8; }  // FIXME
 
  unsigned getCharWidth() const { return 8; } // FIXME
  unsigned getCharAlign() const { return 8; } // FIXME
  
  /// getShortWidth/Align - Return the size of 'signed short' and
  /// 'unsigned short' for this target, in bits.  
  unsigned getShortWidth() const { return 16; } // FIXME
  unsigned getShortAlign() const { return 16; } // FIXME
  
  /// getIntWidth/Align - Return the size of 'signed int' and 'unsigned int' for
  /// this target, in bits.
  unsigned getIntWidth() const { return IntWidth; }
  unsigned getIntAlign() const { return IntAlign; }
  
  /// getLongWidth/Align - Return the size of 'signed long' and 'unsigned long'
  /// for this target, in bits.
  unsigned getLongWidth() const { return LongWidth; }
  unsigned getLongAlign() const { return LongAlign; }
  
  /// getLongLongWidth/Align - Return the size of 'signed long long' and
  /// 'unsigned long long' for this target, in bits.
  unsigned getLongLongWidth() const { return LongLongWidth; }
  unsigned getLongLongAlign() const { return LongLongAlign; }
  
  /// getWCharWidth/Align - Return the size of 'wchar_t' for this target, in
  /// bits.
  unsigned getWCharWidth() const { return WCharWidth; }
  unsigned getWCharAlign() const { return WCharAlign; }

  /// getChar16Width/Align - Return the size of 'char16_t' for this target, in
  /// bits.
  unsigned getChar16Width() const { return Char16Width; }
  unsigned getChar16Align() const { return Char16Align; }

  /// getChar32Width/Align - Return the size of 'char32_t' for this target, in
  /// bits.
  unsigned getChar32Width() const { return Char32Width; }
  unsigned getChar32Align() const { return Char32Align; }

  /// getFloatWidth/Align/Format - Return the size/align/format of 'float'.
  unsigned getFloatWidth() const { return FloatWidth; }
  unsigned getFloatAlign() const { return FloatAlign; }
  const llvm::fltSemantics &getFloatFormat() const { return *FloatFormat; }

  /// getDoubleWidth/Align/Format - Return the size/align/format of 'double'.
  unsigned getDoubleWidth() const { return DoubleWidth; }
  unsigned getDoubleAlign() const { return DoubleAlign; }
  const llvm::fltSemantics &getDoubleFormat() const { return *DoubleFormat; }

  /// getLongDoubleWidth/Align/Format - Return the size/align/format of 'long
  /// double'.
  unsigned getLongDoubleWidth() const { return LongDoubleWidth; }
  unsigned getLongDoubleAlign() const { return LongDoubleAlign; }
  const llvm::fltSemantics &getLongDoubleFormat() const {
    return *LongDoubleFormat;
  }
  
  /// getIntMaxTWidth - Return the size of intmax_t and uintmax_t for this
  /// target, in bits.  
  unsigned getIntMaxTWidth() const {
    return IntMaxTWidth;
  }
  
  /// getUserLabelPrefix - This returns the default value of the
  /// __USER_LABEL_PREFIX__ macro, which is the prefix given to user symbols by
  /// default.  On most platforms this is "_", but it is "" on some, and "." on
  /// others.
  const char *getUserLabelPrefix() const {
    return UserLabelPrefix;
  }
  
  /// getTypeName - Return the user string for the specified integer type enum.
  /// For example, SignedShort -> "short".
  static const char *getTypeName(IntType T);
  
  ///===---- Other target property query methods --------------------------===//
  
  /// getTargetDefines - Appends the target-specific #define values for this
  /// target set to the specified buffer.
  virtual void getTargetDefines(const LangOptions &Opts,
                                std::vector<char> &DefineBuffer) const = 0;
  
  /// getTargetBuiltins - Return information about target-specific builtins for
  /// the current primary target, and info about which builtins are non-portable
  /// across the current set of primary and secondary targets.
  virtual void getTargetBuiltins(const Builtin::Info *&Records, 
                                 unsigned &NumRecords) const = 0;

  /// getVAListDeclaration - Return the declaration to use for
  /// __builtin_va_list, which is target-specific.
  virtual const char *getVAListDeclaration() const = 0;

  /// isValidGCCRegisterName - Returns whether the passed in string
  /// is a valid register name according to GCC. This is used by Sema for
  /// inline asm statements.
  bool isValidGCCRegisterName(const char *Name) const;

  // getNormalizedGCCRegisterName - Returns the "normalized" GCC register name.
  // For example, on x86 it will return "ax" when "eax" is passed in.
  const char *getNormalizedGCCRegisterName(const char *Name) const;
  
  struct ConstraintInfo {
    enum {
      CI_None = 0x00,
      CI_AllowsMemory = 0x01,
      CI_AllowsRegister = 0x02,
      CI_ReadWrite = 0x04,       // "+r" output constraint (read and write).
      CI_HasMatchingInput = 0x08 // This output operand has a matching input.
    };
    unsigned Flags;
    int TiedOperand;
    
    std::string ConstraintStr;  // constraint: "=rm"
    std::string Name;           // Operand name: [foo] with no []'s.
  public:
    ConstraintInfo(const char *str, unsigned strlen, const std::string &name)
      : Flags(0), TiedOperand(-1), ConstraintStr(str, str+strlen), Name(name) {}
    explicit ConstraintInfo(const std::string &Str, const std::string &name)
      : Flags(0), TiedOperand(-1), ConstraintStr(Str), Name(name) {}

    const std::string &getConstraintStr() const { return ConstraintStr; }
    const std::string &getName() const { return Name; }
    bool isReadWrite() const { return (Flags & CI_ReadWrite) != 0; }
    bool allowsRegister() const { return (Flags & CI_AllowsRegister) != 0; }
    bool allowsMemory() const { return (Flags & CI_AllowsMemory) != 0; }
    
    /// hasMatchingInput - Return true if this output operand has a matching
    /// (tied) input operand.
    bool hasMatchingInput() const { return (Flags & CI_HasMatchingInput) != 0; }
    
    /// hasTiedOperand() - Return true if this input operand is a matching
    /// constraint that ties it to an output operand.  If this returns true,
    /// then getTiedOperand will indicate which output operand this is tied to.
    bool hasTiedOperand() const { return TiedOperand != -1; }
    unsigned getTiedOperand() const {
      assert(hasTiedOperand() && "Has no tied operand!");
      return (unsigned)TiedOperand;
    }
    
    void setIsReadWrite() { Flags |= CI_ReadWrite; }
    void setAllowsMemory() { Flags |= CI_AllowsMemory; }
    void setAllowsRegister() { Flags |= CI_AllowsRegister; }
    void setHasMatchingInput() { Flags |= CI_HasMatchingInput; }
    
    /// setTiedOperand - Indicate that this is an input operand that is tied to
    /// the specified output operand.  Copy over the various constraint
    /// information from the output.
    void setTiedOperand(unsigned N, ConstraintInfo &Output) {
      Output.setHasMatchingInput();
      Flags = Output.Flags;
      TiedOperand = N;
      // Don't copy Name or constraint string.
    }
  };

  // validateOutputConstraint, validateInputConstraint - Checks that
  // a constraint is valid and provides information about it.
  // FIXME: These should return a real error instead of just true/false.
  bool validateOutputConstraint(ConstraintInfo &Info) const;
  bool validateInputConstraint(ConstraintInfo *OutputConstraints,
                               unsigned NumOutputs,
                               ConstraintInfo &info) const;
  bool resolveSymbolicName(const char *&Name,
                           ConstraintInfo *OutputConstraints,
                           unsigned NumOutputs, unsigned &Index) const;
  
  virtual std::string convertConstraint(const char Constraint) const {
    return std::string(1, Constraint);
  }
  
  // Returns a string of target-specific clobbers, in LLVM format.
  virtual const char *getClobbers() const = 0;
  

  /// getTargetPrefix - Return the target prefix used for identifying
  /// llvm intrinsics.
  virtual const char *getTargetPrefix() const = 0;
    
  /// getTargetTriple - Return the target triple of the primary target.
  const char *getTargetTriple() const {
    return Triple.c_str();
  }
  
  const char *getTargetDescription() const {
    return DescriptionString;
  }

  struct GCCRegAlias {
    const char * const Aliases[5];
    const char * const Register;
  };

  virtual bool useGlobalsForAutomaticVariables() const { return false; }

  /// getUnicodeStringSymbolPrefix - Get the default symbol prefix to
  /// use for string literals.
  virtual const char *getUnicodeStringSymbolPrefix() const { 
    return ".str";
  }

  /// getUnicodeStringSection - Return the section to use for unicode
  /// string literals, or 0 if no special section is used.
  virtual const char *getUnicodeStringSection() const { 
    return 0;
  }

  /// getCFStringSection - Return the section to use for CFString
  /// literals, or 0 if no special section is used.
  virtual const char *getCFStringSection() const { 
    return "__DATA,__cfstring";
  }

  /// getCFStringDataSection - Return the section to use for the
  /// constant string data associated with a CFString literal, or 0 if
  /// no special section is used.
  virtual const char *getCFStringDataSection() const { 
    return "__TEXT,__cstring,cstring_literals";
  }
  
  
  /// isValidSectionSpecifier - This is an optional hook that targets can
  /// implement to perform semantic checking on attribute((section("foo")))
  /// specifiers.  In this case, "foo" is passed in to be checked.  If the
  /// section specifier is invalid, the backend should return a non-empty string
  /// that indicates the problem.
  ///
  /// This hook is a simple quality of implementation feature to catch errors
  /// and give good diagnostics in cases when the assembler or code generator
  /// would otherwise reject the section specifier.
  ///
  virtual std::string isValidSectionSpecifier(const llvm::StringRef &SR) const {
    return "";
  }

  /// getDefaultLangOptions - Allow the target to specify default settings for
  /// various language options.  These may be overridden by command line
  /// options. 
  virtual void getDefaultLangOptions(LangOptions &Opts) {}

  /// getDefaultFeatures - Get the default set of target features for
  /// the \args CPU; this should include all legal feature strings on
  /// the target.
  virtual void getDefaultFeatures(const std::string &CPU, 
                                  llvm::StringMap<bool> &Features) const {
  }

  /// setFeatureEnabled - Enable or disable a specific target feature,
  /// the feature name must be valid.
  ///
  /// \return - False on error (invalid feature name).
  virtual bool setFeatureEnabled(llvm::StringMap<bool> &Features,
                                 const std::string &Name,
                                 bool Enabled) const {
    return false;
  }

  /// HandleTargetOptions - Perform initialization based on the user
  /// configured set of features.
  virtual void HandleTargetFeatures(const llvm::StringMap<bool> &Features) {
  }

  // getRegParmMax - Returns maximal number of args passed in registers.
  unsigned getRegParmMax() const {
    return RegParmMax;
  }

  // isTLSSupported - Whether the target supports thread-local storage
  unsigned isTLSSupported() const {
    return TLSSupported;
  }

protected:
  virtual uint64_t getPointerWidthV(unsigned AddrSpace) const {
    return PointerWidth;
  }
  virtual uint64_t getPointerAlignV(unsigned AddrSpace) const {
    return PointerAlign;
  }
  virtual enum IntType getPtrDiffTypeV(unsigned AddrSpace) const {
    return PtrDiffType;
  }
  virtual void getGCCRegNames(const char * const *&Names, 
                              unsigned &NumNames) const = 0;
  virtual void getGCCRegAliases(const GCCRegAlias *&Aliases, 
                                unsigned &NumAliases) const = 0;
  virtual bool validateAsmConstraint(const char *&Name, 
                                     TargetInfo::ConstraintInfo &info) const= 0;
};

}  // end namespace clang

#endif
